CSC 15 lab 5


This week's lab will continue to allow you to practice writing functions and
loops, including nested loops.  These basic skills will allow us to write
more interesting programs later.

1. Write a function that takes a string, representing a day of the week
("Sunday" to "Saturday") as an argument, and returns the corresponding number
associated with the day: 0 for Sunday, 1 for Monday, 6 for Saturday, etc.
If the input string is invalid, then return -1.
For example, if your function is called daynum, then calling daynum("Monday")
should return 1, calling daynum("someotherstring") will return -1.

**Do not use more than one if-else statement in the function. Hint:
Days=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"]


1b. Write another function to convert the name of a Month into a number.
This time however, calling monthnum("January") should return 1, not 0.
Calling monthnum("December") should return 12.  Return -1 if the input
parameter is not valid.


1c. The following array contains the number of days in each month, starting
with Januray.  We'll assume that it's not a leap year so Feburary has
28 days:

DM = [31,28,31,30,31,30,31,31,30,31,30,31]

Write a function "daysin" that takes a STRING representing the Month
and returns the number of days in the month.  So daysin("Feburary") should
return 28, daysin("December") should return 31.  Return 0 if the argument
is an invalid string.

Do not do this from scratch: write this function by calling the other
function(s).


2. Write a NESTED loop that prints the following:

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5 
...

Your print statements may print AT MOST ONE number at a time.
Encapsulate your loop into a function that can print an arbitrary
number of lines of this pattern.

2b.  Now do this one:

5
5 4
5 4 3
5 4 3 2 
5 4 3 2 1


2c. And this one (challenge)

        1
      2 1
    3 2 1
  4 3 2 1
5 4 3 2 1

You must use nested loops and your solution must be generalizable.



The following problems were optional last week but required this week:



3.  Write a function that takes an array parameter and return
    the same array without duplicates.  For example, calling
    nodups([3,4,1,3,5,1] should return [3,4,1,5].  All duplicates are
    removed.  Hint: don't try to delete an element from an array.  Instead,
    construct a new array, starting from [], that does not include
    duplicates.

4.  Modify problem 1 of lab 4 so that the function returns an array
    containing the indices of all occurrences of the largest element.  For
    example, largests([3,5,8,2,8,4]) should return [2,4] because the largest
    element (8) is found at positions 2 and 4 in the array.
    THIS FUNCTION WILL BE CRUCIAL FOR THE NEXT LAB.



5. (Challenge) In football, scores are in the following units:

   8: touchdown + 2 points
   7: touchdown + 1 point
   6: touchdown with no extra points
   3: field goal
   2: safety

You're to write a function to print all the possible ways for a
team to score a given number of points (which will be the parameter to
the function) For example, 16 points can be made up of 1 touchdown 
(with +1 point) and 3 field goals, or 2 touchdowns and 1 safety, 
or 8 safeties, etc.  If the input number of points is 1 or negative, 
your program should print "impossible to score that many points."  
However, there is exactly one way to score 0 points.  You need to print 
ALL possible ways to score the given number of points as well as count how 
many ways there are to score the points.